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Topic: Itoigawa or Kishu? (Read 15671 times)

I know everyone probably has their preference, and I know basically the difference in looks between the two varieties, but are there any differences in growth habits and the way you work an itoigawa vs. a kishu? I had my first real encounter with an itoigawa just a couple weeks ago, since much of the shimpaku around San Diego seems to be kishu (the couple sources that I know of, anyway).

Love to hear your experiences with either or both of these!

Jason

PS I've found Brent Walston's catalog at Evergreen Gardenworks to have some of the best descriptions on the net of the different juniper varieties.

like them both, though John's point about foliage size is to be considered. I too have had SPider Mites on both, Itoigawa (my favorite) can also be a little touchy. So weigh your choices and decide on a tree by tree basis. On really big trees I like the Tohaku (native) foliage, can make for a nice tree as well. I don't know how many other named varieties/regional isloates there are, but there seem to be quite a few. John

Jason,We have a few hundred kishu and itoigawa growing in the ground, side by side. Same water, same fertilizer (lots). Here's the obvious difference:1. The kishu extend much faster. The new shoots are much longer. But, they don't "trunk up" like the itoigawa.2. The itoigawa have less extension, tighter foliage. After a few years, the itoigawa look like they are smaller, but they have grown notably thicker trunks/nebari, compared to the kishu.3. There is a definite difference in foliage color, when you see them side by side.

So, that's the difference we see when we grow them. I don't know if that helps you buying an unknown tree.

When developing shohin, itoigawa does look better with it's smaller foliage but it also does revert to juvenile foliage more readily than Kishu when cutting back harder - at least here in New England. Urushibata san said that there are about many different 'isolates' (as John K said) or sub-varieties of itoigawa, some stronger than others.John R

Thanks for the wisdom! What about being grafted trees? Are there any differences in how the varieties respond when grafted onto San Jose, or are all of the aforementioned differences pretty much retained?

It's interesting to read Peter Tea's post "Field Trip to Obuse Part 2" and learn that Itoigawa is in fashion currently in Japan. I'd recommend it if you have not read it already. For a while now I have always been told the foliage size should somewhat match the size of the tree, however those are some big junipers with small Itoigawa foliage.

Yeah, I got some late last year from Travis Goldstein of California bonsai studio. My teacher and I ended up grafting a California juniper I have I think it was Feb with some scions we got from several Itoigawa's he has growing in the ground at the Huntington Gadens. We put about 10 or so grafts on it. 1 or 2 at the base of every major branch. All are still alive, but have not busted out of their grafting tape "cocoon". He is preety good at it and the tree has been out of the shady area of the yard for a while, so I'm sure most of those scions will take off. In the mean time, I have started dozen's of Itoigawa cuttings. I bought some hormex # 8 off ebay, dipped the cuttings in it ( I use all size cutting's, from just a few needles, to a small woody branch) and put them in flats of pure perlite that are covered by a plastic dome. this is all set on a seedling heat mat put next to a south facing window. None have died off after a month. I have noticed a difference in quality of various Itoigawa. The itoigawa from Chikugo-en in the south bay area of Los Angeles (Gary Ishi) seems to be the tightest. My teacher has a yamadori itoigawa (Not a graft, Old Japanese import) and although it's an awesome and beautiful chuchin size tree, the foilage on it is not as tight as the Chikugo-en Itoigawa graft's. Now I'm looking for good quality Tosho for graft donors. There are different quality with Tosho needle juniper also.

Chris,In my area of the country, I experience the exact opposite regarding thickening and trunking up for Shimpaku. Kishu here thicken at double the rate of Itoigawa! Runner growth is around three times as large as well. Itoigawa are proving to be super finicky for me in the deep south, while Kishu seem to love it. I think the reason for this is simple: in their native habitat, Itoigawa grows where it is pretty cold and dry, while Kishu grows where it is warm and humid. An interesting point to consider regarding "best" variety for you and your region. A sidenote: I was told by a prominent American figure that an artist in Japan famous for his various Shimpaku kept 30 or 40 different "stock strains", all with different characteristics, such as rapid root production for root grafting, rapid thickening, quick callous formation, in addition to foliage. While cutting grown Shimpaku of Itoigawa and Kishu with great foliage will thicken eventually, it's a Pretty slow process. From the little story above I've mostly abandoned it in favor of Hollywoods and Parson's which trunk up rapidly, literally 10 times faster, with the eventual goal of grafting better foliage when the trunk is finished.